DESCRIPTION

ac prints out a report of connect time (in hours) based on the lo-
gins/logouts in the current wtmp file. A total is also printed out.
The accounting file wtmp is maintained by init(8) and login(1). Nei-
ther ac nor login creates the wtmp if it doesn't exist, no accounting
is done. To begin accounting, create the file with a length of zero.
NOTE: The wtmp file can get really big, really fast. You might want
to trim it every once and a while.
GNU ac works nearly the same u*x ac, though it's a little smarter in
several ways. You should therefore expect differences in the output of
GNU ac and the output of ac's on other systems. Use the command info
accounting to get additional information.

OPTIONS

-d, --daily-totals
Print totals for each day rather than just one big total at the
end. The output looks like this:
Jul 3 total 1.17
Jul 4 total 2.10
Jul 5 total 8.23
Jul 6 total 2.10
Jul 7 total 0.30
-p, --individual-totals
Print time totals for each user in addition to the usual every-
thing-lumped-into-one value. It looks like:
bob 8.06
goff 0.60
maley 7.37
root 0.12
total 16.15
people Print out the sum total of the connect time used by all of the
users included in people. Note that people is a space separated
list of valid user names; wildcards are not allowed.
-f, --file filename
Read from the file filename instead of the system's wtmp file.
--complain
When the wtmp file has a problem (a time-warp, missing record,
or whatever), print out an appropriate error.
--reboots
Reboot records are NOT written at the time of a reboot, but when
the system restarts; therefore, it is impossible to know exactly
when the reboot occurred. Users may have been logged into the
system at the time of the reboot, and many ac's automatically
count the time between the login and the reboot record against
the user (even though all of that time shouldn't be, perhaps, if
the system is down for a long time, for instance). If you want
to count this time, include the flag. *For vanilla ac compati-
bility, include this flag.*
--supplants
Sometimes, a logout record is not written for a specific termi-
nal, so the time that the last user accrued cannot be calculat-
ed. If you want to include the time from the user's login to
the next login on the terminal (though probably incorrect), in-
clude this you want to include the time from the user's login to
the next login on the terminal (though probably incorrect), in-
clude this flag. *For vanilla ac compatibility, include this
flag.*
--timewarps
Sometimes, entries in a wtmp file will suddenly jump back into
the past without a clock change record occurring. It is impos-
sible to know how long a user was logged in when this occurs.
If you want to count the time between the login and the time
warp against the user, include this flag. *For vanilla ac com-
patibility, include this flag.*
--compatibility
This is shorthand for typing out the three above options.
-a, --all-days
If we're printing daily totals, print a record for every day in-
stead of skipping intervening days where there is no login ac-
tivity. Without this flag, time accrued during those interven-
ing days gets listed under the next day where there is login ac-
tivity.
--tw-leniency num
Set the time warp leniency to num seconds. Records in wtmp
files might be slightly out of order (most notably when two lo-
gins occur within a one-second period - the second one gets
written first). By default, this value is set to 60. If the
program notices this problem, time is not assigned to users un-
less the --timewarps flag is used.
--tw-suspicious num
Set the time warp suspicious value to num seconds. If two
records in the wtmp file are farther than this number of seconds
apart, there is a problem with the wtmp file (or your machine
hasn't been used in a year). If the program notices this prob-
lem, time is not assigned to users unless the --timewarps flag
is used.
-y, --print-year
Print year when displaying dates.
-z, --print-zeros
If a total for any category (save the grand total) is zero,
print it. The default is to suppress printing.
--debug
Print verbose internal information.
-V, --version
Print the version number of ac to standard output and quit.
-h, --help
Prints the usage string and default locations of system files to
standard output and exits.

FILES

wtmp
The system wide login record file. See wtmp(5) for further de-
tails.

AUTHOR

The GNU accounting utilities were written by Noel Cragg
<noel@gnu.ai.mit.edu>. The man page was adapted from the accounting
texinfo page by Susan Kleinmann <sgk@sgk.tiac.net>.